Seat reservations and viewing on the apps

I bought the Global Pass, read that I have to have seat reservations on my trains.  Which I did.  To download this on my app it wants a DNR , which 7 digits on your confirmation email.  With seat reservations I did not receive a DNR.  I haven't activated my pass yet for my trip in the summer.  I am booking seat reservations for the travel from London to Milan, and each city I plan to visit. I'm getting nervous, I would hate to be in London and found out I did this wrong!  I booked on Eurostar and had no problem, it's on my app. But when using Bahn app for seat reservations to Würzburg, I received an email but no 7 digits to download on the app. Help me understand this, please!